This invention relates to an integrated circuit device of large scale integration (LSI) which contains circuit elements poched at a high density, and more particularly, to a large scale semiconductor integrated circuit device using a polycrystalline silicon layer.
As is well known a conventional integrated circuit device contains a plurality of mutually isolated circuit elements in a semiconductor substrate which are interconnected by means of metal wiring paths provided on the surface of the substrate. The circuit elements are connected to the wiring paths through contact holes or openings formed in an insulating layer which covers the circuit elements.
However, manufacturing an integrated circuit device of high density and of large scale integration by such conventional technique for circuit configuration has required a great number of very minute contact holes, which have not been able to be attained without a very advanced technology for processing miniature patterns. Since there is a limit to fineness of a pattern which can be realized, integration beyond a limited scale has been impossible with the conventional technique.